It may sound silly, but in printing there are many ways to produce the colour black. Mono printing – in black only – uses a single ink, but for full colour printing we recommend using Rich Black, which is a combination of CMYK – Cyan, Magenta, Yellow, Key (Black). The extra ink produces a deeper, more saturated black colour.
The two colours might look identical on screens, but in print there will be a difference in colour, and each has their own purpose. In short, standard black is used for text, fine lines, and for economical print jobs. Rich black is used for large text, and all images in full colour printing.